Vault alarm timer switch



1964 F. o. JOHNSON 3,145,271

VAULT ALARM TIMER swrrcu Filed Sept. 5,1962

3 Sheets-Sheet l NIGHTS OF PROTECTION Aug.. 18, 1964 F. o. JOHNSON- VAULT ALARM TIMER SWITCH 3 Sheets-Sheet 2 Filed Sept.- 5, 1962 Aug. 18, 1964 F. o. JOHNSON 3,145,271

VAULT ALARM TIMER SWITCH Filed Sept. 5, 1962 3 Sheets-Sheet 3 l I I I I I I I I l I I l I I I I I l I I l I I I I l l I I I I l i i /2 9 I l I I I I I I l I I I I l l I I I l l I I I I I I l I I I I I I l l l United States Patent Office 3,145,271 Patented Aug. 18, 1964 3,145,271 VAULT ALARM TIMER SWITCH Fred 0. Johnson, Northport, N.Y., assignor to American District Telegraph Company, Jersey City, N.J., a corporation of New Jersey Filed Sept. 5, 1962, Ser. No. 221,472 11 Claims. (Cl. 209-38) or disable the electric protection circuits at the desired hour in the morning so that authorized persons may enter the protected area without causing an alarm to be sounded. In essence, such devices are electric clocks which can be manually preset to operate electrical contacts after a prescribed interval, yet the peculiar service requirements for a vault alarm timer are such as to preclude the use of ordinary industrial timers.

A vault alarm timer requires accuracy in its ability to measure elapsed time and also in the method by which the various settings are accomplished. It is obviously desirable to have the timer function accurately at the set hour since too early operation leaves the vault unprotected and too late operation means either a delay in the days business or a false alarm if the vault is opened before the 7 time cycle is completed. When closing the vault there maybe three settings required which affect the accuracy of the time interval. First, the timer clock must be set to agree with the time of day, if for any reason it should be at variance therewith. Second, a setting must be made for the desired hour of opening in the morning should it be different from the previous opening hour. Thus while the normal opening might be at 8:00 a.m., there are often occasions when it is desired to open at 7:00 a.m., 9:00 em. or some other hour. Finally, itis necessary to make a setting for the number of nights that will pass before the vault is to be opened, i.e., for an ordinary week day when the vault will be opened in the morning, the setting will be for one night, but on Friday, when the opening will not occur until Monday, the setting will be made for three nights.

Any error made in any setting will be reflected in the time the device functions to switch the protection circuits to the normal day time condition. And so will other errors introduced by the backlash inherent in the long gear trains and the slippage of the friction drivers employed in the prior art; in fact it has not been unusual to have the accumulated. errors amount to as much as 45 minutes.

The principal object of the present invention has been to provide an electrical timer of improved accuracy and reliability.

Another object of the invention has been the provision of an electrical timer for vaults and the like having novel and improved means for time setting adjustment which avoid the necessity for fine, closely spaced graduations used in prior art devices and which frequently result in substantial errors.

A feature of the invention has been the provision of an electrical timer for vaults and the like with a se1fcentering device to facilitate daily setting.

Another feature of the invention has been the provision of an electrical timer for vaults and the like operated by a positive one-way drive.

Another feature of the'invention has been the provision of an electrical timer for vaults and the like which uses a minimum number of gears, thus avoiding the errors inherent from the backlash of long gear trains.

Another object of the invention has been the provision of an electrical timer for vaults and the like which combines a high degree of accuracy with an improved ease and simplicity of operation and a relatively low cost.

Other and further objects, features and advantages of the invention will'appear more fully from the following description of the invention taken in connection with the appended drawings, in which:

FIG. 1 is a front elevational view of a vault alarm timer embodying the invention;

FIG. 2 is a left side elevational view of the timer of FIG. 1;

FIG. 3 is a front elevational view of the vault alarm timer of FIG. 1 with the parts mounted on the front of the front frame plate omitted to illustrate more clearly the parts located inwardly of the front frame plate; and

FIG. 4 is a partial longitudinal sectional view taken along the line 4-4 of FIG. 3.

Referring now to the drawings, reference numeral 10 denotes a front plate, which may be made of relatively heavy gauge sheet steel and which is provided withscrew holes 11 for attachment of the unit to any suitable support. Front plate 10 has marked thereon in a circular pattern a series of graduations forming a time-of-day dial or clock 12. The dial 12 has the hours from 1 to 12 marked thereon and may conveniently be provided with intermediate lines representing'five minute intervals.

The dial 12 has a" central circular aperture in front of which is mounted an annular disk having marked along the outer circumference thereof a series of graduations forming an opening-time dial 13. The dial 13 has the hours from 1 to 12 marked thereon and may conveniently be provided with intermediate lines representing 10 minute intervals. The dial 12, its central aperture, and dial 13 are concentric.

As is best shown in FIG. 4, a shaft 14 extends axially through the center of the aperture in dial 12. Shaft 14 is rotatably mounted in a central axially extending aperture in a pinion 15. An annular hub portion 16 at the forward end of pinion 15 fits in the aperture in dial 12. Pinion 15 is staked or otherwise afidxed to the plate 10 so as to remain stationary.

A hub 17 is mounted on shaft 14 forwardly of plate 10. The hub 17 is pinned to shaft 14 by a pin 18 acting in aligned holes in shaft 14 and hub 17 so that hub 17 rotates with shaft 14. Dial 13 is mounted on hub 17 and is staked thereto so as to rotate with hub 17 and hence also with shaft 14.

A transparent annular disk 19 is freely mounted on hub 17. The outside diameter of disk 19 is preferably the same as the outside diameter of dial 12 marked on face plate 10. A knurled knob 20 is threaded on the outer end of hub 17 and, when tightened down, presses disk 19 tightly against the face of dial 13 so that disk 19 and knob 20 will rotate with dial 13. An indicator line 21 extends radially across the inner portion of disk 19. A pin 22 is mounted in a radially extending aperture in the outer portion of disk 19, pin 22 constituting an extension of indicator line 21.

A rectangular aperture 23 is provided in disk 19 in alignment with pin 22. The aperture 23 is surrounded by a protective forwardly projecting frame 24. A thin rectangular block 25 of magnetic metal, e.g., steel, is rotatably mounted on pin 22 within aperture 23. One face of block 25 bears the legend AM. and the other face RM.

A magnet 26 is mounted on the rear of face plate 10 by means of a clip 27, the magnet being aligned with an aperture 28 in face plate 10. Aperture 28 is radially aligned with the 12 oclock graduation of dial 12. The

arrangement is such that, as disk 19 is rotated, block 25 passes aperture 28 and the leading edge of block 25 is attracted by magnet 26, causing block 25 to pivot about pin 22. As block 25 continues past aperture 28, the pivoting action continues until block 25 has been rotated through an arc of 180. Hence, each time block 25 passes aperture 28, block 25 is rotated so that the A.M. face is replaced by the RM. face, and vice versa. The shielding effect of steel plate will prevent any action of magnet 26 on block until the leading edge of block 25 becomes aligned with aperture 28.

A frame'plate 29 is supported rearwardly of front plate 10 by means of four cylindrical spacers 30 which are held by screws 31 acting through holes in plate 29 and screws 32 acting through holes in plate 10.

An electric motor unit 33 is mounted on the rear of plate '29 by means of screws 34. The electric motor unit may be of any suitable constant speed type, such as the type 117? synchronous motor sold by Cramer Controls Corp. Other constant speed clock motor mechanisms may be used. For the embodiment of the invention described, the output speed of the motor unit 33 should be r.p.h., i.e., 2 revolutionsper day. The motor unit should be provided with a one-way overriding clutch which permits rotation in only one direction, in this case, a clockwise direction when viewed from the front.

The motor unit output stub shaft is shown at 34'. The stub shaft 34 is rigidly coupled to the inner end of shaft 14 by a coupling bushing 35 having set screws 36 and 37 contacting shafts 14 and 34, respectively.

It will be evident that shaft 14 rotates at a constant speed of A r.p.h. when motor unit 33 is powered. Hence, dial 13 and disk 19 will likewise rotate at a constant speed of r.p.h. Thus, if the angular position of disk 19 is set so that indicator line 21 is aligned initially with the correct time of day on dial 12, the time of day may thereafter be read from dial 12 by noting the position of indicator line 21 relative to dial 12. While dial 12 is calibrated only from 0 to 12 hours, the correct time on a 24 hour basis is shown by the position of block 25 which reads either AM. or PM, as described above.

The time of day may easily be set by rotating knurled knob 20 in a clockwise direction (FIG, 1) until indicator line 21 is aligned with the correct time on dial 12. A further 360 rotation may be necessary if the AM.- RM. designation is incorrect. Reverse rotation of knob 20 will unthread this knob frorn hub 17. But, even if knob 20 is very tightly threaded on hub 17, re verse rotation of knob 2t) cannot produce reverse rotation of shaft 14 because of the one-way overriding clutch referred to, which prevents reverse rotation of the motor unit.

An arm 38 has a central aperture mounted on a reduced diameter hub 39 of coupling 35. Arm 38 is staked or otherwise affixed to coupling 35 so that arm 38 will rotate with coupling 35 and hence at the speed of motor shaft 34.

Near one end of arm 38 there is provided a threaded aperture into which is threaded one end of a stub shaft 40. A collar 41 is mounted on shaft forwardly of arm 38 and a gear 42 is rotatably'rno'unted on shaft 40 forwardly of collar 41. A screw 43 acting in a threaded hole in the forward end of shaft 40 holds gear 42 on shaft 40 and in contact with collar 41. Gear 42 is arranged to mesh with pinion 15 so that gear 42' will walk around pinion 15 as shaft 14 is rotated. The ratio between gear 42 and pinion 15 is 2:1, so that it requires two complete revolutions of arm 38 to cause gear 42 to make one complete revolution about the axis of shaft 40. A pin 44 mounted in an aperture in the front face of gear 42 projects forwardly from that face.

As best shown in FIG. 2, a shaft 45 is rotatablyjournaled at the rear end thereof in a hole in frame plate 29. Shaft 45 projects forwardly through a corresponding hole in front face plate 10, which hole acts as a forward journal for shaft 45. A knurled knob 46 is mounted on touch the bottom of the slot.

4 the forward end of shaft 45, being attached thereto by a screw 47 acting in a hole in a hub portion of knob 46 and against shaft 45. A collar 48 is mounted on shaft 45 adjacent the rear or inside face of plate 10, the collar 48 being pinned to shaft 45 by a pin 4% acting in aligned holes in collar 48 and shaft 45.

A star wheel 50 is rigidly mounted on a rearwardly projecting hub portion 51 of collar 48. .As is best shown in FIG. 3, star wheel 54) has eight V-shaped notches in the periphery thereof extending over a peripheral arc of about 240. These notches are designated, respectively, OFF, 1, 2, 3, 4, 5, 6 and 7. The radius of the periphery of wheel 50 between the end walls of notches OFF and 7 is the same as the radius of the notch bases.

An arm 52 is pivotally mounted on the rear face of plate 10 by a screw 53 acting in a threaded hole in plate 10. At one end thereof, arm 52 has a rearwardly inclined tab 54 which has a hole in which is engaged one end of a spring 55. The other end of spring 55 is attached to a pin 56 projecting rearwardly from the rear face of plate 10.

At the other end thereof, arm 52 carries a rearwardly projecting pin 57 on which is rotatably mounted a roiler 58. The arrangement is such that spring 5% urges arm 52 to pivot about screw 53 in a counterclockwise direction (FIG. 3), which in turn urges roller to enter the adjacent one of the notches in the periphery of star wheel 50. The diameter of roller 58 is selected so that the roller 58 seats comfortably in the slot but does not Thus, roller 58 and its pivoted mounting acts as a self-centering device for the star wheel, always providing a predetermined angular position of the star wheel for each of the notches. in order for shaft 45 and star whel 59 to be rotated, sufficient rotational force must be exerted to cause roller 58 to ride out of the slot in which it is resting against the action of spring 55.

Pin 44 projecting from gear 42 is arranged to contact the wall of an adjacent one of the star wheel notches once for every two revolutions of gear 42, which corresponds to once every two revolutions of shaft 14, or,

in other words, once in each 24 hour period. Contact between pin 44 and a star wheel slot wall will advance the star wheel one notch. it will be evident that this mechanism is essentially a geneva movement affording a one-notch star wheel advance for each 24 hour period. And, by reason of the spring-urged roller 58, the star wheel as always comes to rest in a centered position.

As best shown in FIG. 1, knob 46 carries a pointer 59 which is arranged to be aligned successively with calibrations OFF, 1, 2, 3, 4, 5, 6 and I of a nights-cf-protection dial 6t on the front face of plate 149. The pointer 59 is arranged to be aligned with the respective calibrations on dial so at the same time that roller 5? is resting in the corresponding respective slots in star wheel 5t Star wheel 56, and hence also dial 6%, may be set to any one of the positions thereof by manual rotation of knob 46. Stops 61 and 62 at the OFF and 7 positions, respectively, of dial as prevent rotation of star wheel 5% beyond the arc defined by the star wheel slots.

With star wheel Stl in the OFF position thereof, i.e., with roller 58 resting in the OFF slot, pin 44 will miss the star wheel 59 and hence rotation of shaft will not result in any change of position of the star wheel 59. But, in each of the other star wheel positions, the pin 44 will advance the star wheel one position each day until the OFF position is reached.

A cam 63 is rigidly mounted on a hub projecting forwardly from a collar 64.near the rear end of shaft 45. Collar 64 is pinned to shaft 45 by a pin 65 acting in aligned holes in collar 64 and shaft 45. A multi-blade leaf switch 66 is mounted on the front face of frame plate 29 by screws 67. Switch as has a laterally projecting lug 63 (FIG. 3) arranged to ride on the'periphery of cam 63, as a cam follower, under the urging of a spring (not shown). A slot 69 is provided in the periphery of cam 63 at a position located so that lug 68 will enter slot 69 when star wheel 50 moves to its OFF position. The result is a switching action of switch 66 when the OFF position is reached. The circuit changes produced by this switching action may be selected as desired. Typically, they will involve sending to the central station an opening or protectionofi signal and a resetting of the protection system to the day condition. However, a variety of other signalling actions may be performed, e.g.,

freeing or opening an electrical locking mechanism for the vault or other protected space.

For operation of the timer, the opening time must be set on dial 13. This is done by backing off slightly knob to free disk 19 and then rotating disk 19 until indicator line 21 is aligned with the desired opening time on dial 13, e.g., 8 oclock, as shown. The disk 19 may require an additional 360 rotation to cause the opening time to be AM. or P.M., as desired This will be indicated by the position of block when indicator line 21 passes the time of day on dial 12 corresponding to the opening time. Knob 20 is then tightened so that disk 19 will be locked to dial 13.

The correct time of day is next set by rotating knob 20 in a clockwise direction until indicator line 21 is aligned with the correct time on dial 12. A further 360 rotation may be required so that block 25 will correctly indicate am. or p.m., as thecase may be.

Next, dial 69 is set for the number of nights of protection desired by rotating knob 46 until pointer 59 is aligned with the corresponding number on dial 60. This will cause star Wheel 50 to rotate until roller 58 is resting in the corresponding star wheel slot. Typically, on aweek day one night of protection will be desired, while on a weekend three nights of protection will be desired. With the construction illustrated, any number of nights from 1 to 7 may be selected.

Assuming that the timer is set at 5 pm. on a Friday for opening at 8 am. Monday (three nights of protection), the operation will be as follows; Motor 33 will rotate shaft 14 at the rate of 2 revolutions per day, in turn rotating dial 13 and disk 19 at this rate. Roller 58 will initially be resting in star wheel notch No. 3. When 8 am. Saturday is reached, pin 44 will contact a wall of star Wheel notch No. 1, advancing the star wheel to the next position in which roller 58 rides in notch No. 2. At 8 am. Sunday, pin 44 will contact a Wall of star Wheel notch No. OFF, advancing the star wheel to the next position in which roller 58 rides in notch No. 1. At 8 am. Monday, pin 44- will contact a wall of the star Wheel beyond the OFF notch (the Wall designated 70 in FIG. 3), advancing the star wheel to the final position in which roller 53 rides in the OFF notch. In this position of the star Wheel, cam 63 Will be located so that lug 58 enters notch 69, thus providing the desired electrical circuit changes representing the opening conditions.

While the invention has been described in connection with a specific embodiment thereof and in a specific use, various modifications thereof will occur to those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

l. A timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a selected speed, a fixed dial calibrated in secle'cted time units; a rotatable dial calibrated in selected time units, means intercoupling said rotatable dial and said first shaft for rotating said rotatable dial at a speed fixedly related to said selected speed, indicator means arranged to rotate With said rotatable dial and to traverse said fixed dial so as to indicate the passage of time on said fixed dial relative to said rotatable dial, said indicator means being independently traversable along said rotatable dial, means to set said indicator means to any selected time unit on saidrotatable dial, a second shaft, operating means, means selectively to the selected time unit on said rotatable dial.

2. A timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a selected speed, a fixed dial calibrated in selected time units, a rotatable dial calibrated in said time units, means intercoupling said rotatable dial and said first shaft for rotating said rotatable dial at a speed fixedly related to said selected speed, indicator means arranged to rotate with said rotatable dial and to traverse said fixed dial so as to indicate the passage of time on said fixed dial relative to said rotatable dial, said indicator means being manually traversable along said rotatable dial, means to set said indicator means to any selected time unit on said rotatable dial, a second shaft, electrical switching means, means selectively to set said second shaft in any one of a plurality of successive discrete angular positions including a final position, means connected to and operated by said second shaft for operating said switching means when said second shaft enters said final position thereof, and intermittent motion means intercoupling said first and second shafts and arranged to move said second shaft between successive ones of said discrete angular positions each time said indicator means passes a particular calibration on said fixed dial corresponding to the selected time unit on said rotatable dial.

3. A vault alarm timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a selected speed, a fixed dial calibrated in selected time units, a rotatable dial calibrated in said time units, means intercoupling said rotatable dial and said first shaft for rotating said rotatable dial at a speed fixedly related to said selected speed, indicator means arranged to rotate with said rotatable dial and to traverse said fixed dial so as to indicate the passage of time on said fixed dial relative to said rotatable dial, said indicator means being manually traversable along said rotatable dial, means to set said indicator means to any selected time unit on said rotatable dial, a second shaft, electrical switching means, cam means carried on said second shaft for rotation therewith, cam follower means intercoupling said switching means and said cam means, means selectively to set said second shaft in any one of a plurality of successive discrete angular positions including a final position, said cam means and said cam follower means being arranged to operate said switching means when said second shaft enters said final position thereof, and intermittent motion means intercoupling said first and second shafts and arranged to move said second shaft between successive ones of said discrete angular positions each time said indicator means passes a particular calibration on said fixed dial corresponding to the selected time unit on said rotatable dial.

4. A vault alarm timer as set forth in claim 3 in which said intermittent motion means comprises a geneva movement.

5. A vault alarm timer as set forth in claim 4 in which said geneva movement comprises a fixed pinion surrounding said first shaft, a gear meshing with said pinion and coupled with said first shaft for rotation as said first shaft rotates whereby said gear Walks around said pinion, a star wheel mounted on and rotating with said second shaft, and means carried by said gear and arranged to contact said star wheel to move said star wheel through an arc corresponding to the angular distance between successive ones of said discrete angular positions each time said first shaft passes through a preselected multiple of a complete revolution.

6. A vault alarm timer as set forth in claim comprising means automatically to center said star wheel in the respective positions thereof corresponding to said discrete angular positions.

7. A vault alarm timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a selected speed, a fixed clock dial calibrated in time units, a rotatable clock dial calibrated in time units and positioned concentrically with said fixed dial, indicator means rotatably mounted relative to said fixed and rotatable dials and having an indicator linetraversable along said clock dials, releasable means to lock said indicator means to said rotatable dial so that motion of said indicator line along said fixed dial indicates the passage of time on said fixed dial relative to said rotatable dial, a second shaft, a star wheel mounted on said second shaft for rotation therewith, said star wheel having a series of peripheral notches, manually operable means to set said star wheel at any one of a plurality of successive discrete angular positions thereof, an arm affixed to said first shaft for rotation therewith, a fixed pinion, a gear rotatably mounted on said arm and being engaged with said pinion whereby said gear walks around said pinion as said shaft rotates,

,a pin carried on and projecting from said gear, said pin being arranged to contactsaid star wheel to advance the same through an arc corresponding to the distance between adjacent notches each time said indicator line passes the time on said fixed dial corresponding to the setting of said indicator line relative to said rotatable dial, a cam mounted on said second shaft and rotatable therewith, electrical switching means, and cam follower means intercoupling said switching means and said cam, said cam and said cam follower means being arranged to operate said switching means when said star wheel reaches a final angular position thereof.

8. A vault alarm timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a selected speed, a fixed clock dial calibrated in time units, a rotatable clock dial calibrated in time units and positioned concentrically with said fixed dial, atransparent disk rotatably mounted relative to said fixed and rotatable dials and having an indicator line traversable along said clock dials, releasable means to lock said disk to said rotatable dial so that motion of said indicator line along said fixed dial indicates the passage of time on said fixed dial relative to said rotatable dial, a second shaft, a star wheel mounted on said second shaft for rotation therewith, said star wheel having a series of peripheral notches, a pivotally mounted roller arranged to enter successive ones of said notches as the same pass a position fixed relative to said star wheel, means to urge said roller into said notches whereby contact of said roller and the walls of said notches act to center said star wheel relative to said fixed position, manually operable means to set said star wheel at any one of the angular positions thereof in which said roller engages a respective one of said notches, a fixed pinion surrounding said first shaft and arranged so that said first shaft is rotatable relative to said pinion, an arm afiixed to said first shaft for rotation therewith, a gear rotatably mounted on said arm and being engaged with said pinion whereby said gear walks around said pinion as said shaft rotates, a pin carried on and projecting from said gear, said pin being arranged to contact said star wheel to advance the same through an arc corresponding to the distance between adjacent notches each time said indicator line passes the time on said fixed dial corresponding to the setting of said indicator line relative to said rotatable dial, a cam mounted on said second shaft and rotatable therewith, electrical switching means, and cam follower means intercoupling said switching means and said cam, said cam and said cam follower means being arranged to operate said switching means when said star wheel reaches a final angular position thereof.

9. A vault alarm timer, comprising a constant speed motor mechanism, a first shaft coupled to said motor mechanism for rotation at a speed of two revolutions per day, a fixed clock dial calibrated in hours from 1 to 12, a rotatable clock dial calibrated in hours from 1 to 12 and positioned concentrically with said fixed dial, a trans parent disk rotatably mounted relative to said fixed and rotatable dials and having an indicator line traversable along said clock dials, releasable means to lock said disk to said rotatable dial so that motion of said indicator line along said fixed dial indicates the passage of time on said fixed dial relative to said rotatable dial, a display member pivotally mounted on said disk and having calibrations representative of am. and pm. located thereon so as to be displayed in opposite pivoted positions of said display member, means to pivot said display member from one to the other of said positions thereof each time said display member passes a fixed point relative to said fixed dial, a second shaft, a star wheel mounted on said second shaft for rotation therewith, said star wheel having a series of peripheral notches, a pivotally mounted roller arranged to enter successive ones of said notches as the same pass a position fixed relative to said star wheel, means to urge said roller into said notches whereby contact of said roller and the walls of said notches act to center said star wheel relative to said fixed position, manually operable means to set said star wheel at any one of the angular positions thereof in which said roller engages a respective one of said notches, a fixed pinion surrounding said first shaft and arranged so that said first shaft is rotatable relative to said pinion, an arm affixed to said first shaft for rotation therewith, a gear rotatably mounted on said arm and being engaged with said pinion whereby said gear walks around said pinion as said shaft rotates, a pin carried on and projecting from said gear, said pin being arranged to contact said star wheel to advance the same through an arc corresponding to the distance between adjacent notches each time said indicator line passes the time of day on said fixed dial corresponding to the setting of said indicator line relative to said rotatable dial, a cam mounted on said second shaft and rotatable therewith, electrical switching means, and cam follower means intercoupling said switching means and said cam, said cam and said cam follower means being arranged to operate said switching means when said star wheel reaches a final angular position thereof.

10. A vault alarm timer as set forth in claim 9 in which said means to pivot said display member comprises a magnet positioned to pivot said display member through an arc of each time said indicator line traverses a selected time unit on said fixed dial.

11. A vault alarm timer as set forth in claim 9, comprising a front frame plate of magnetic material, said fixed dial being formed by calibrations marked in a circular pattern on said plate, said plate having an aperture adjacent to the 12 oclock calibration on said fixed dial, and a magnet mounted on the rear of said plate adjacent said aperture whereby said display member is attracted by said magnet each time said display member passes said aperture.

References tIited in the file of this patent UNITED STATES PATENTS 2,832,856 Goodhouse Apr. 29, 1958 

3. A VAULT ALARM TIMER, COMPRISING A CONSTANT SPEED MOTOR MECHANISM, A FIRST SHAFT COUPLED TO SAID MOTOR MECHANISM FOR ROTATION AT A SELECTED SPEED, A FIXED DIAL CALIBRATED IN SELECTED TIME UNITS, A ROTATABLE DIAL CALIBRATED IN SAID TIME UNITS, MEANS INTERCOUPLING SAID ROTATABLE DIAL AND SAID FIRST SHAFT FOR ROTATING SAID ROTATABLE DIAL AT A SPEED FIXEDLY RELATED TO SAID SELECTED SPEED, INDICATOR MEANS ARRANGED TO ROTATE WITH SAID ROTATABLE DIAL AND TO TRAVERSE SAID FIXED DIAL SO AS TO INDICATE THE PASSAGE OF TIME ON SAID FIXED DIAL RELATIVE TO SAID ROTATABLE DIAL, SAID INDICATOR MEANS BEING MANUALLY TRANSVERSABLE ALONG SAID ROTATABLE DIAL, MEANS TO SET SAID INDICATOR MEANS TO ANY SELECTED TIME UNIT ON SAID ROTATABLE DIAL, A SECOND SHAFT, ELECTRICAL SWITCHING MEANS, CAM MEANS CARRIED ON SAID SECOND SHAFT FOR ROTATION THEREWITH, CAM FOLLOWER MEANS INTERCOUPLING SAID SWITCHING MEANS AND SAID CAM MEANS, MEANS SELECTIVELY TO SET SAID SECOND SHAFT IN ANY ONE OF A PLURALITY OF SUCCESSIVE DISCRETE ANGULAR POSITIONS INCLUDING A FINAL POSITION, SAID CAM MEANS AND SAID CAM FOLLOWER MEANS BEING ARRANGED TO OPERATE SAID SWITCHING MEANS WHEN SAID SECOND SHAFT ENTERS SAID FINAL POSITION THEREOF, AND INTERMITTENT MOTION MEANS INTERCOUPLING SAID FIRST AND SECOND SHAFTS AND ARRANGED TO MOVE SAID SECOND SHAFT BETWEEN SUCCESSIVE ONES OF SAID DISCRETE ANGULAR POSITIONS EACH TIME SAID INDICATOR MEANS PASSES A PARTICULAR CALIBRATION ON SAID FIXED DIAL CORRESPONDING TO THE SELECTED TIME UNIT ON SAID ROTATABLE DIAL. 